I'm not sure what your variables are, but I will try task 3 with you.
y=$500(in billions)
x= the number of years that have passed since 2009
percentage of decrease: 1 - % =
so your formula will look like this: y(1 - %)^x
6 is your answer, hope it helped
Answer:
(-5, -4) is -9
Step-by-step explanation:
hope this helps